In a related application, Fabrication of Thin Film Germanium Infrared Sensor by Bonding to Silicon Wafer, Ser. No. 10/993,533, filed Nov. 19, 2004, and Germanium Infrared Sensor for CMOS Imagers. Ser. No. 11/069,422, filed Feb. 28, 2005, we disclosed how a germanium IR detector may be formed on a silicon CMOS circuit by a bonding process, in which either a germanium donor wafer or a germanium epi wafer was used. Because the size of commercially available germanium wafers are smaller than that of silicon wafers, the foregoing processes cannot take advantage of larger size silicon wafers. Additionally, consistently good quality germanium-epi film on silicon wafer are difficult to fabricate. Further, germanium film transfer is a complex process.
Liu et al. reported a liquid-phase epitaxy technique to fabricate germanium on insulator, Liu et al., High-quality single-crystal Ge on insulator by liquid-phase epitaxy on Si substrates, Appl Phys Lett, 2004, 84, 2563. This technique requires careful temperature control in order to initiate the recrystallization at the predetermined seeding region.